关于数字判断的问题

413xp

1. check()
   
2. {
   
3.    case "$1" in
   
4.        *[!0-9]*) echo "no"
   
5.                  ;;
   
6.        *       ) echo "check $1"
   
7.                  ;;
   
8.    esac
   
9. 
   
10. 
    
11. }
    
12. 
    
13. check2()
    
14. {
    
15.     if [[ $1 =~ *[!0-9]* ]];then
    
16.         :
    
17.     else
    
18.         echo "check2 $1"
    
19.     fi
    
20. }
    
21. 
    
22. check3()
    
23. {
    
24.     if [[ $1 =~ ^[0-9]+$ ]];then
    
25.         echo "check3 $1"
    
26.     fi
    
27. }

复制代码

请问下 为什么 *[!0-9]*在check 和check2里的表现不同，个人理解*[!0-9]*写法应该是不正确才对的，但是在check里面又能正确判断出数字

yinyuemi

回复 1# 413xp


   

       [...]  Matches any one of the enclosed characters.  A pair of characters separated by a hyphen denotes a
              range expression; any character that sorts between those two  characters,  inclusive,  using  the
              current  localeâs  collating sequence and character set, is matched.  If the first character fol-
              lowing the [ is a !  or a ^ then any character not enclosed is matched.   The  sorting  order  of
              characters  in range expressions is determined by the current locale and the value of the LC_COL-
              LATE shell variable, if set.  A - may be matched by including it as the first or  last  character
              in the set.  A ] may be matched by including it as the first character in the set.

413xp

看的不太明白了，谢谢了，
经过测试，check2里面，不管是字符还是数字，它永远是false，不管那个了，最好的写法应该是check3吧，记住这个就算了回复 2# yinyuemi